Portable electronic devices have advanced to multimedia devices which offer various services such as voice and video telephony functions, an information input/output function, and data storage.
As devices with various capabilities are increasingly used, designers have focused on improving device performance, including battery lifetime, battery charging time and charging mechanisms. Hence, recent electronic devices allow not only wired charging but also wireless charging. In these devices, if both wired and wireless chargers are connected, the battery is selectively charged by a charging module using one of the wired and wireless chargers.
Electronic devices providing a Universal Serial Bus (USB) On-The-Go (OTG) function have been developed. The OTG function enables electronic devices such as a Personal Digital Assistant (PDA), MP3 player, mobile phone, mouse, keyboard, or an external memory, to communicate with one another through the USB without using a computer. For example, an OTG operation can transfer data by connecting the external memory to the mobile phone through the USB.
Typically, in the OTG operation for USB communication between devices, a device acting as a server supplies battery power to a client device. Accordingly, the remaining battery power of the server device is gradually reduced during the OTG operation, and the battery needs to be charged to continue the OTG operation. Conventional devices handle this task by selectively supplying the power to the OTG client using the charging module, or disconnecting the OTG device and then charging the battery through the wireless charger.